Update done with https://github.com/rtyley/bfg-repo-cleaner/pull/425 - updating to this Scala version should be invisible to users.

I've had to change the implementation of the --replace-text feature (using https://github.com/rtyley/line-break-preserving-line-splitting rather than the abandoned scala-io library), it should be-like-for-like, and has been fairly extensively tested, but let me know if you encounter any weird issues.